Containers are widely used in the consumer products industry to hold consumable products such as food items, for example, strawberries and cookies, and items such as screws and pins. Such items are often relatively small and sold in batches. For example, a container of strawberries may contain 25 strawberries and a container of screws may contain 200 screws. Containers containing such goods are displayed in retail stores where consumers can view and inspect them, and typically place them into a shopping, cart should a consumer choose to purchase a container of such goods.
Such containers are typically constructed from transparent plastic so that consumers can see the goods without opening the container. Allowing consumers to open a container prior to purchasing it can raise several issues. If a consumer knows that other consumers are able to open and touch or remove items, then the consumer is likely to be concerned that some items may have been removed or, in the case of food particularly, that the items have been touched in an unsanitary manner or in a manner that may otherwise make the goods less desirable or useful. Vendors are similarly concerned that such tampering with goods may dissuade consumers from purchasing containers of such items and that they may incur liability if tampering has occurred that may endanger a purchaser or make the items in the container incompatible with the terms of sale, particularly if a container may be opened and re-sealed without leaving evidence of such actions. Thus both consumers and vendors have an interest in goods being sold in containers that are resistant to such tampering, or at least are designed to leave clear evidence of such tampering after it occurs.
Thermoformed plastic containers are in wide use for consumer goods. In some cases, the container is formed so that it is permanently sealed and can only be opened by cutting or tearing the plastic. While this approach results in clear evidence of tampering, it also means that the package is not re-sealable. It is often highly desirable for such containers to be re-sealable so that a consumer can remove some items from the container and leave the remaining items in the container for future use. If the container cannot be re-sealed, then the remaining items are more likely to be accidentally lost, or be spoiled. For a food container, it is generally very desirable that the container can be re-sealed to minimize the exposure of the contents to ambient air which can result in food spoiling more quickly than it would if it were isolated from such ambient air.